British art has historically had an uncomfortable relationship with the avant-garde. For centuries there was a smack of the cultural cringe about our attitude to modernity, with native artists long looking abroad or to imports such as Holbein and Van Dyck for exemplars of what and how to paint. The first home-grown group to make an explicit claim to radicalism was the Pre-Raphaelite Brotherhood in 1848, and it was radical primarily in the sense that it looked backwards rather than forwards. It was to be half a century before another gang of bristling young men, the Vorticists, set out systematically to reappraise how painting and sculpture dealt with the modern age.

Vorticism was a product of the first decades of the 20th century — the age of the ism. The late Edwardian summer was also a period of artistic extremism: Post-Impressionism, Fauvism and Cubism were born in France, Futurism in Italy, the germs of Constructivism formed in Russia, Dadaism and Surrealism in France and Spain. Underlying most of these movements was a repudiation of traditional representation or themes and the search for a new way to take apart and then reconstruct form. And while the mood may have been pan-European the nationalist flavours were sharp.

Ironically, Vorticism, although a fiercely British movement, was the work of a cosmopolitan group. Its éminence grise was the American poet Ezra Pound, its leader was the Canadian-born writer-artist Percy Wyndham Lewis, closely affiliated members included the Anglo-American sculptor Jacob Epstein and the tragic Frenchman Henri Gaudier-Brzeska. The leading pure-blood Brits were William Roberts and Edward Wadsworth. The Vorticists at Tate Britain (until September 4) is an examination of this short-lived but important grouping and through it a look at Modernism and the culture wars of the period at their most vibrant stage.

Vorticism was given its name by Pound who explained: "The Vortex is the point of maximum energy. It represents, in mechanics, the greatest efficiency." Wyndham Lewis described it more as a new way of seeing: "A man who passes his days amid the rigid lines of houses, a plague of cheap ornamentation, noisy street locomotion, the Bedlam of the Press, will evidently possess a different habit of vision to a man living amongst the lines of a landscape."

What this translated into on canvas were fractured, geometrical abstract forms — jagged shapes like broken glass, often outlined in black and filled in with areas of flat colour, that teeter on the edge of representation. It was the antidote to Bloomsbury mimsiness; what Wyndham Lewis, who was as dab a hand with invective as he was with a brush, characterised as "this family party of strayed and Dissenting aesthetes" with its "mid-Victorian languish of the neck".

The work produced by the Vorticists, and Wyndham Lewis in particular, couldn't be less languishing. With its lightning-bolt forms and electrical crackle their art — when noticed by the wider public — came as a shock and not one necessarily to take seriously. At the only Vorticist group exhibition in Britain, in June 1915, the art critic of the Daily Mirror noted drily of the painters, many of whom had volunteered for the Army: "It is evident that in the combat somebody has been badly knocked about."

The images now, however, seem both brave and prescient. The machine aesthetic of the work and the grids and planes that evoke skyscrapers and vertiginous, metropolitan vistas are a vision of the 20th century that came to pass. But the artists could summon up beauty too. Wadsworth's woodcuts are models of concision and clarity of purpose; Dorothy Shakespear's watercolours offset their angularity with sumptuous colour; Wyndham Lewis canvases, The Crowd of 1914-15 for example, have a Fritz Lang skittishness. The sculptors too made work unlike anything previously seen: Epstein had already caused a celebrated furore with his naked figures for the BMA headquarters on the Strand in London and he continued to carve pieces that were all about primal urges — whether of power or of sex. Gaudier-Brzeska meanwhile produced strange hybrids of fish merging with torpedoes or a massive hieratic bust of Ezra Pound which, when viewed from behind, is a giant phallus.